Tvheadend

If you don't want to VPN then you have two options:

1) Add port forwarding to your home router to connect to ports 9981 and 9982 on your TVH box - how you do this depends on the router you have. Making stuff accessible to the outside world like this is a security risk.

2) Add port forwarding to your home router to connect to port 22 on your TVH box, and activate an ssh server if you don't have one already. If your router supports it, use a different external port to forward to 22, otherwise your logs will be filled up with script-kiddie access attempts. Then use ssh port forwarding to access your TVH box from the outside world, e.g. ssh -p <portno> -L 9981:localhost:9981 -L 9982:localhost:9982 addr.of.home.net - where <portno> is the external port you're forwarding on your router. Then point your client at localhost:9981 & 9982

Note:

Both options require you to have a publicly accessible address. Unless you have a static IP address, you'll need to set up a dynamic DNS address - there are a number of providers who will do this for free.

Option 2) is more secure, but because the link is encrypted, you may find you have bandwidth limitations depending on the CPU capabilities of the devices at each end of the ssh link. You could mitigate this if you have a more grunty box than the Pi on you home network - in that case you'd set the port forwarding on your router to point to port 22 on the more powerful box, and change your ssh command to: ssh -p <portno> -L 9981:<addr.of.pi>:9981 -L 9982:<addr.of.pi>:9982 addr.of.home.net - where <addr.of.pi> is the LAN IP address of the pi.